ZTFM  S555C1 – Hobbyist edition 2708 EPROM – 1983

Thanks to the input of a reader I updated the East German CPU page to be much more accurate as to the various institutions that existed, and their respective logos.  There were institutions in three different cities (Erfurt, Frankfurt, and Dresden), and they had amongst them 7 different names and a variety of logos.

It helps to remember that IC’s were made different in East Germany.  There was not so much corporations as we think of them in the West such as Intel or AMD that made this or that.  In East Germany (and the USSR) IC’s (and most everything else) were made by institutions, that were typically a government organization, or sanctioned by the government to do/make certain things.  These could be changed, consolidated, opened/closed at the whim of the government resulting in a lot of confusion in identity.  Add to that the changes brought with the fall of communism, and these institutions transition to modern corporation and you get some very interesting collecting opportunities.

The updated page should help ID’ing them a bit easier.

Cadence Palladium II Processor MCM 1536 cores – 128MB GDDR – Manufactured by IBM

Several years ago we posted an unusual MCM that’s purpose was a mystery.  It was clearly made by IBM and clearly high end.  While researching another mystery IBM MCM both of their identities came to light.  The original MCM is an emulation processor from a Cadence Palladium Emulator/Accelerator system.

In the 1990’s IBM had been working on technology to make emulating hardware/software designs more efficient as such designs got more complicated.  At the time it was most common to emulate a system in an FPGA for testing, but as designs grew more complex this became a slower and slower process.  IBM developed the idea of an emulation processor.  This was to be known as CoBALT (Concurrent Broadcast Array Logic Technology).  It was licensed to a company called QuickTurn in 1996.  At its heart the QuickTurn CoBALT was a massively parallel array of boolean logic processors.  Boolean processors are similar to a normal processor

Here is a flipped (and very rough) die from a Palladium II. You can make out the very repeating design of the 768 boolean processors.

but only handle boolean data, logic functions such as AND, OR, XOR, etc.  Perhaps the most well known, is the boolean sub-processor that Intel built into the 8051, it excelled at bit manipulation.  The same applies for the emulation processors in CoBALT.  Each boolean processor has at its heart a LUT (Look Up Table), with 8-bits to encode the logic function (resulting in 256 possible logic function outputs) and the 3 gate inputs serving as an index into the LUT, as well as the associated control logic, networking logic, etc.

A target design is compiled and emulated by the CoBALT system.  The compiling is the tricky part, the entire design is broken down into 3-input logic gates, allowing the emulator to emulate any design.  Each processor element can handle one logic function, or act as a memory cell (as many designs obviously include memory).  The CoBALT had 65 processors per chip, and 65 chips per board, with a system supporting up to 8 boards.  This 33,280 processor system could compile 2 Million gates/Hour.  The CoBALT plus sped this up a bit and supported 16 boards, doubling capacity and added on board memory.

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Signetics 2650I – Original Version from May of 1976

The Signetics 2650 processor has always been described as ‘very mini-computer like’ and for good reason, it truly is very minicomputer like in design.  It is an 8-bit processor released in July of 1975 made on an NMOS process.  The 2650 has a 15-bit address bus (the upper bit (16) is reserved for specifying indirect addressing) allowing addressing of up to 32K of memory.  It has 7 registers, R0, which is used as an accumulator, as well as 2 banks of 3 8-bit registers accessed.  The 2650 supports 8 different addressing modes, including direct, and indirect with autoincrement/decrement.  Its clearly a mini-computer design and there is a reason for that, it was based on one.

The 2650 is very closely based on the IBM 1130 mini-computer released in 1965.  Both use 15-bit addressing, many addressing modes, and a set of 3 registers (Signetics added support for 2 banks of 3,  The Signetics 2650 is often noted for its novel use of a 16-bit PSW status register, but this too is from the 1130, which used a 16-bit Device Status Register for talking with various I/O components.  So why would Signetics base a processor released in 1975 on a 1965 mini-computer?

Because the 2650 was not designed long before it was released.  J. Kessler  was hired by Signetics in 1972 in part to help design an 8-bit processor.  Kessler was hired by Jack Curtis, (Of Write Only Memory fame) from…IBM. Kessler designed the architecture very similar to the IBM 1130 and Kent Andreas did the silicon layout.  The design contains 576 bits of ROM (microcode mainly), ~250 bits of RAM (for registers, stack, etc) and about 900 gates for logic.  Clock speed was 1.25MHz (2MHz on the -1 version) on a ion implanted NMOS process, very good for 1972 (this was as fast as the fastest IBM 1130 made), but Signetics was tied up working with Dolby Labs on audio products (noise canceling etc) and didn’t have the resources (or perhaps the desire) to do both, so the 2650 was pushed back to 1975.  In 1972 the IBM 1130 it was inspired by was still being made.  If the 2650 had been released in 1972 it would have had the Intel 4004 and 8008 as competition, both of which were not easy to use, and had complex power supply and clocking requirements.  The 2650 needed a 5V supply, and a simple TTL single phase clock.

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ARM946E on a Chartered Semiconductor 0.18u Process

ARM is one of the most popular RISC cores used today, and has been for over a decade now.  ARM is an IP company. They license processor designs/architectures for others to use, but do not actually manufacturer the processors themselves….or do they?

ARM offers a variety of cores, and licenses them in a variety of different ways.  There are, in general, three main ways to get an ARM design.  Larger companies with may resources (such as Apple, Broadcom, or Qualcomm) will purchase an ARM architecture license.  This isn’t specific to any ARM core in particular (such as say a ARM946) but the entire ARM architecture, allowing these companies to design their own ARM processors from the ground up.  This takes a lot of resources and talent that many companies lack.

Second, ARM offers RTL (Register Transfer Level) processor models, these are provided in a hardware programming language such as VHDL or Verilog.  They can be dropped into a design along with other IP blocks (memory, graphics, etc) and wrapped with whatever a company needs.  This is a fairly common method, and typically the lest expensive.  It does require more work and testing though.  Designing a chip is only part of the process. Once it’s designed it still must be fab’d.

ARM7EJ-S on a TSMC 0.18u Process. Wafer #25 from June 2003

ARM also offers ARM models that are transistor level designs, pre-tested on various fab processes.  Pre-tested means exactly what it sounds like. ARM designed, built and had them manufactured, fixing any problems, and thus giving the ability to say this core will run at this speed on this fab’s process.  Testing and validation may often go as far as testing a particular fab’s particular process, in a particular package.  Its more work, and thus cost more, but these make for drop in ARM cores. Want to use a ARM946 core, on a TSMC 0.18u process in a lead free Amkor BGA package? Yah ARM’s tested that and can provide you with a design they know is compatible.  This allows extremely fast turn around from concept, to design to silicon.

In the below picture (click to enlarge) you can see a large variety of ARM cores from the early 2000’s. They span ARM7, ARM9, ARM10 and ARM11 designs.  Each is marked with info as to what exactly it is.  The core name, the revision (such as r2p0, meaning major revision 2, pass/subversion 0) as well as the Fab (TSMC, UMC, SMIC, Chartered) and the design node (all of these are either 0.18 or 0.13u processors).

21 Various ARM design tet chips from TSMC, UMC, Charted, covering many ARM cores.

Also noted on some is the exact wafer the die was cut from, this is typical on VERY early production tests, usually first run silicon, so they can identify any physical/manufacturing defects easier.  Some design modifications have little to do with the processor itself, but are done to increase yields on a given process/node.

ARM926EJ on a UMC 0.13u Process. 

Package type (in this case most are Amkor BGA) and other features are noted.  Many say ‘ETM’ which is ARM’s Embedded Trace Macrocell, a debugging tool that allows instruction and date traces of an in operation core, very useful for debugging. ARM offers ETM for each of their processor types (ETM9 for example covers all ARM9 type cores) and itself has a revision number as well.

Some of these chips come in an interesting BGA package. The package has a removable die cover for inspection/testing (and possibly modification). Note the large die in the ARM926EJ on the left, though the processor core itself is very small (its in the upper left only a few square mm).  This is done to facilitate bonding into the package, In this type of package there wouldn’t be any way to connect all the bonding wires to the very tiny ARM core, so the die has a lot of ‘wasted’ space on it.

So does ARM make processors? Yup! but only for internal use, to help develop the best possible IP for their clients.